Lift control system for press unloader or the like

ABSTRACT

There is herein disclosed a lift control system for a press unloader having an extendable and retractable jaw means for gripping and removing a part from the die cavity of a press with pivotal frame means supporting the jaw means for pivotal movement to lift the part from the die cavity and interconnected air operated power cylinder means to sequentially extend the jaw means, grip the part, lift the part, and retract the jaw means.

United States Patent 1191 Cagle [4 1 May 15, 1973 [54] LIFT CONTROLSYSTEM FOR PRESS 3,178,040 4/1965 Nelson ..214/1 BB UNLOADER OR THE LIKE2,763,229 9/1956 Sahlin ..214/l BB X [75] Inventor: Harlan R. Cagle,Clarkston, Mich. Primary Examiner Gerald M Forlenza [73] Assignee:Sahlin Engineering Company, Inc., 3m?! illiill'liflfi ffil filk r.WQFE?!Troy, Mich. Att0rney-Harness, Dickey and Pierce 22 Filed: May 27, 1971[57] g pp 147,367 There is herein disclosed a lift control system for apress unloader having an extendable and retractable [52] U S CI 214/1 BD214/1 BB jaw means for gripping and removing a part from the [51] 623/00 die cavity of a press with pivotal frame means support g the jmeans for pivotal movement to lift the p [58] Field of Search ..214/1 B,1 BS, 1 EV, from the di cavity and interconnected air 0 erated 214/1 BD147T 188 p power cylinder means to sequentially extend the jaw means,grip the part, lift the part, and retract the jaw [56] References Citedmeans.

7 Claims, 3 Drawing Figures LIFT CONTROL SYSTEM FOR PRESS UNLOADER ORTHE LIKE BACKGROUND AND SUMMARY OF THE- INVENTION While the concept andprinciples of the present invention may be applicable to various typesof apparatus and environments, the invention disclosed herein relatesgenerally to press unloading apparatus and, more particularly, to pressunloading devices of the type disclosed in US. Pat. Nos. 2,609,776 and3,206,040 and to control systems therefor of the type disclosed in US.Pat. Nos. 3,474,825; 3,436,186; and 3,394,650.

It is the primary object of the present invention to provide new andimproved means for lifting a formed part out of a die cavity in a pressprior to removal of the part from the press cavity. To this end, a newand improved air operated control system has been devised in which thenumber of parts required to achieve the desired results has beenreduced, the parts of the system have been arranged in a new andimproved manner facilitating assembly, operation, and repair, and newand improved parts have been devised for the system.

In the presently preferred embodiment of the inventive concepts andprinciples, a first air operated power cylinder means actuates jaw meanscarried by the press unloader device between an extended part grippingposition in the press cavity and a retracted position while a second airoperated power cylinder means moves the jaw means between the extendedpart gripping position and a lift position prior to return movement ofthe jaw means to the retracted position. The second cylinder means isconnected to high pressure air inlet hoses and exhaust hoses in serieswith thefirst cylinder means and providedwith integral control meanseffecting a time delay of operative connection to the jaw means wherebythe desired sequential operation of the apparatus is obtained. It iscontemplated that the inventive concepts are also applicable to fluidoperated power cylinder apparatus generally whenever a time delayoperation is required. Thus, in the broadest aspects of the invention,the power cylinder apparatus may be air operated or hydraulicallyoperated and associated with any kind of machinery, particularlymaterial handling equipment.

BRIEF DESCRIPTION OF THE DRAWING The presently preferred embodiment isillustrated in the accompanying drawing wherein:

FIG. 1 is a side elevational view of a portion of a press unloadingdevice incorporating the inventive concepts and principles;

FIG. 2 is an enlarged cross-sectional view of a portion of the apparatusof FIG. 1; and

FIG. 3 is another enlarged cross-sectional view of a portion of theapparatus of FIG. 2 in a different operational position.

DETAILED DESCRIPTION Referring now to FIG. 1, the bottom portion of aconventional swinging arm type press unloader is shown to comprise aswingable support arm 10, a fixed support frame means 12, adjustablyconnected to and carried by the support arm, a movable support framemeans 14 pivotally mounted on the fixed support frame, an air operatedpower cylinder means 16 pivotally mounted on the fixed support frame 12and pivotally operably connected to the movable support frame 14, and apart gripping unit 18 carried by the movable support frame.

The part gripping unit 18 comprises jaw means 20 movable between aretracted position, as shown by the solid lines of FIG. 1, and anextended part gripping position, shown in phantom at 20a and 20b, by anair operated power cylinder means 22. The jaw means is also movablebetween an open release position, as shown by the solid lines of FIG. 1and a closed part gripping position as shown at 20a and 20b. The movablesupport frame 14 and unit 18 are pivotally movable between the extendedpart gripping position 20a and a lift position as shown at 20b to enablethe part 24 to be lifted clear of the die cavity in the press.

Referring now to FIGS. 2 and 3, the air operated power cylinder means 16comprises a cylindrical member 30 having pivotal connecting means in theform of spaced opposite end plates 31, 32 and tie plates 33, 34 securedby suitable fastening means 35. The cylinder is pivotally mounted onfixed support frame 12 by bearing members 36, 37 rotatably mounted insupport arms 38, 39 fixed to plate 12 and threadably mounted in cylinderend plate 32 at the bottom of the power cylinder. The cylinder 16 isoperatively connected to the movable frame means 14 by a movable pistonrod 40 and pivotal connecting means in the form of a bearing sleeve 42and a bearing shaft 44 pivotally mounted in arm portions 46, 47 fixed onthe movable frame. A conventional high pressure air source 48 isconnected to the power cylinder 16 through conventional control valvemeans 49 by air hose means 50, 52 and to the power cylinder 22 by airhose means 54, 56. 'Air hose 52 is attached to the pivotally mountedbearing member 37 by a conventional threaded coupling (not shown)mounted in a threaded portion 57 of a central air passage 58 so as to bepivotally movable therewith and air hose50 is similarly attached to thepivotally mounted bearing shaft 44 by a threaded portion 59 of a centralair passage 60. Air passage 58 is connected to one side 61 of thecylinder through air passage means comprising a chamber 62, an annularinlet passage 64, a valve chamber 66, and an inlet passage 68. Chamber62 is also connected to the same side of the cylinder through an airoutlet passage and a valve chamber 72. An adjustable needle valve 74 isthreadably adjustably mounted in bearing member 36 and valve chamber 66to regulate the rate of flow of inlet air through passage 68 and thuscontrol the rate of movement of piston rod 40 as will be hereinafterdescribed. A spring loaded ball type check valve 76 is mounted in valvechamber 72 to prevent passage of inlet air and permit passage of exhaustair. Air passage 60 is connected to the other side 80 of the powercylinder by air passage means comprising reduced diameter passage 82, avalve chamber 84, a transverse passage 86, an annular chamber 88,axially extending passage portions 90, 92 in the piston rod 40, and atransverse outlet passage 94. Passage 60 is also connected to the sameside of the power cylinder through passage 82, valve chamber 96, annularchamber 88, and passages 90, 92, 94. An adjustable needle valve 97 isadjustably threadably mounted in bearing member 44 and valve chamber 84to regulate the flow of high pressure air through inlet passage 86 and aspring loaded ball type check valve 98 is mounted in valve chamber 96 toprevent passage of inlet air while permitting passage of exhaust air.

The piston rod means 40 includes a tubular portion 100 slidablysupported in suitably sealed bearing means 101 in end plate 32 and areduced diameter member 102 having axially spaced abutment flanges 103,104 providing piston connecting means located at opposite ends of aslide rod portion 106. A piston means 108, comprising a bearing sleeve 110, a disc 1 l2, and sealing means 114, 116, is slidably mounted on theslide rod for movement between the abutment flanges 103, 104 to providetiming means to prevent movement of the piston rod 40 until after thejaw means have been properly positioned.

A spring loaded relief valve 118 is mounted in end plate 31 and extendsinto a chamber 122 which receives piston rod flange 103 in an uppermostposition, FIG. 3, whereat valve 118 is positively opened to allow anyair trapped in chamber portion 80 to escape through a port 126. A sea]128 engages the flange 103 in the fully extended position to prevent anyleakage of high pressure inlet air.

In operation, with the apparatus in the position shown by the solidlines of FIGS. 1 and 2, at a predetermined time valve 49 is actuated todeliver high pressure air from source 48 to one side of power cylinders16, 22 through air lines 50, 56 while exhausting air from the other sideof the cylinders through air lines 54, 52. The high pressure air in line56 is immediately effective to actuate power cylinder 22 to extend andthen close the jaw means on the part 24 over a predetermined timeinterval of, for example, one or two seconds. During the jaw extensionand clamping time period, some of the high pressure air in line 50 alsoflows through passages 60, 82, past needle valve 97, through passages86, 88, 90, 92, 94 into chamber 80 wherein it acts against the adjoiningsurfaces and gradually moves the piston 108 from the solid line fullyretracted position to an intermediate dotted line position 108a whereatthe piston engages the flange abutment 104 to begin to move the pistonrod 40. The air in chamber 80 also acts against the abutment flange 103to keep the piston rod in the retracted position until the pistonengages the other abutment flange and acts against the seal 128 toprevent escape of high pressure air through valve 118. The rate of airflow is adjusted by needle valve 97 so as to move the piston 108 at arate causing engagement of the piston with the piston rod abutmentflange 104 after the jaw means has been extended and closed. Then whenthe piston moves the piston rod to the solid line fully extendedposition 108b, FIG. 3, the bearing housing 42, bearing shaft 44, supportarms 46, 47, and the movable support frame 14 are moved downwardly aboutpivot means 136, FIG. 1, from the normal position parallel to the fixedplate 12 to an inclined position 14b whereat the jaw means and part 24are lifted clear of the die cavity.

Then the high pressure air source 48 is connected by valve 49 to airhoses 52, 54 while hoses 50, 56 are connected to exhaust. Again the highpressure air is immediately effective to reversely actuate powercylinder 22 to retract and then open the jaw means at a predeterminedpoint to release the part after a predetermined time interval. Duringthe jaw retraction and opening time period, some of the high pressureair also flows through chamber 62, passage 64, valve chamber 66, andpassage 68 to chamber 61 wherein it is effective to move the piston,without the piston rod, from the fully extended solid line position1081) of FIG. 3 to the dotted line position 1086 whereat the pistonengages the flange 103 and begins to move the piston rod 40. The highpressure air in chamber 61 also acts against flange 104, which is seatedon end plate 32, to hold the piston rod in the fully extended positionuntil the piston engages the other flange 103. The rate of air flow isadjusted by needle valve 74 so as to move the piston 108 at a ratecausing engagement with the abutment flange 103 after the jaw means andthe part gripped thereby have clearedthe die cavity. The rate of travelof the piston may be varied to return the movable frame 14 to theparallel position at any desired time in relationship to the position ofthe jaw means being actuated to the fully retracted position by powercylinder 22. It will be understood that when the piston 108 moves in onedirection by application of high pressure air to one side or the other,the air on the opposite side is exhausted through the ball valves 76, 98which are opened during exhaust due to pressure differential while beingmaintained closed during application of the high pressure air due to thesprings and a pressure balance in the system.

It is contemplated that the inventive concepts and principles hereindisclosed may be variously otherwise embodied and it is intended thatthe appended claims cover alternative embodiments except insofar aslimited by the prior art.

I claim:

1. A control system for a press unloader having a movable arm carryingjaw means movable between a retracted position and an extended positionfor gripping a part in a die cavity and for carrying the part away fromthe die cavity, comprising air operated jaw operating power cylindermeans for moving the jaw means between the extended position and theretracted position, frame means pivotally supporting said jaw operat ingpower cylinder means and said jaw means, air operated frame operatingpower cylinder means for pivotally moving said frame means jaw operatingpower cylinder means and said jaw means between a part gripping positionand a part lifting position whereby a gripped part is lifted from a diecavity in a press with which the press unloader is associated, timingmeans integral with said air operated frame operating power cylindermeans to cause the pivotal movement after the jaw means has beenextended and the part gripped, a pair of high pressure air hose meansconnected to said air operated jaw operating power cylinder means andsaid air operated frame operating power cylinder means to deliver highpressure air thereto and to exhaust air therefrom, said air operated jawoperating power cylinder means and said air operated frame operatingpower cylinder means being connected in series, first and second pivotalconnecting means between said air operated frame operating powercylinder means and said frame means, one of said. air hose means beingconnected to said power cylinder means through one of said pivotalconnecting means, and the other of said air hose means being connectedto said power cylinder means through the other of said pivotalconnecting means.

2. A control system for a press unloader having a movable arm carryingjaw means movable between a retracted position and an extended positionfor gripping a part in a die cavity and for carrying the part away fromthe die cavity, comprising air operated jaw operating power cylindermeans for moving the jaw means between the extended position and theretracted position, frame means pivotally supporting said jaw operatingpower cylinder means and said jaw means, air operated frame operatingpower cylinder means for pivotally moving said frame means jaw operatingpower cylinder means and said jaw means between a part gripping positionand a part lifting position whereby a gripped part is lifted from a diecavity in a press with which the press unloader is associated, timingmeans integral with said air operated frame operating power cylindermeans to cause the pivotal movement after the jaw means has beenextended and the part gripped, an air cylinder having spaced end walls,piston means in said air cylinder movable therein by air pressure duringand after movement of said jaw means to the extended position, pistonrod means operable by said piston and operably associated with saidframe means to cause pivotal movement thereof, and connecting meansoperable after the movement of said jaw means to the extended positionto connect said piston means and said piston rod means to said framemeans to cause pivotal movement thereof, said piston means beingslidably supported on and movable relative to said piston rod meansduring the first portion of the piston movement, said piston means beingmovable relative to said piston rod means during movement of said jawmeans to the extended position, and said connecting means connectingsaid piston means to said piston rod means after the movement of saidjaw means to the extended position during the last portion of themovement of said piston means.

3. The invention as defined in claim 2 and there being air flow rateadjustment means to control the rate of movement of said piston means bycontrolling the rate of flowof air to enable said jaw means to reach theextended position before said connecting means is effective to connectsaid piston means to said piston rod means.

4. The invention as defined in claim 3 and wherein said connecting meanscomprising spaced abutment flanges on said piston rod means engageablewith said piston means after sliding movement of said piston meanstherebetween.

5. The invention as defined in claim 4 and wherein said spaced abutmentflanges alternately engaging opposite ones of said spaced end walls ofsaid air cylinder and being held thereagainst by high pressure air untilsaid piston means engages one of said abutment flanges and moves saidrod means.

6. A control system for a press unloader having a movable arm carryingjaw means movable between a retracted position and an extended positionfor gripping a part in a die cavity and for carrying the part away fromthe die cavity, comprising air operated jaw operating power cylindermeans for moving the jaw means between the extended position and theretracted position, frame means pivotally supporting said jaw operatingpower cylinder means and said jaw means, air operated frame operatingpower cylinder means for pivotally moving said frame means jaw operatingpower cylinder means and said jaw means between a part gripping positionand a part lifting position whereby a gripped part is lifted from a diecavity in a press with which the press unloader is associated, timingmeans integral with said air operated frame operating power cylindermeans to cause the pivotal movement after the jaw means has beenextended and the part gripped, a first frame means fixed to the movablearm, a second frame means pivoted to the first frame means andsupporting said jaw means, said frame operating power cylinder meanscomprising an air cylinder, a movable piston, and a piston rod, a firstpivotal connecting means pivotally mounting said frame operating powercylinder means between said air cylinder and said first frame means onsaid first frame means, a second pivotal connecting means between saidpiston rod and said second frame means whereby said frame operatingpower cylinder means is movable relative to said first frame means andsaid second frame means during pivotal dis placement of said secondframe means, air hose means connected to said frame operating powercylinder means to supply high pressure air thereto and exhaust airtherefrom, a first air hose connection integral with said first pivotalconnecting means, first air passage means extending from said first :airhose connection through said first pivotal connecting means to one sideof said piston, a second air hose connection integral with said secondpivotal connecting means, and second air passage means extending fromsaid second air hose through said second pivotal connecting means andsaid piston rod to the other side of said piston.

7. The invention as defined in claim 6 and further comprising adjustablevalve means in each of said first and second passage means to variablycontrol the rate of flow of high pressure air to said air cylinder.

1. A control system for a press unloader having a movable arm carryingjaw means movable between a retracted position and an extended positionfor gripping a part in a die cavity and for carrying the part away fromthe die cavity, comprising air operated jaw operating power cylindermeans for moving the jaw means between the extended position and theretracted position, frame means pivotally supporting said jaw operatingpower cylinder means and said jaw means, air operated frame operatingpower cylinder means for pivotally moving said frame means jaw operatingpower cylinder means and said jaw means between a part gripping positionand a part lifting position whereby a gripped part is lifted from a diecavity in a press with which the press unloader is associated, timingmeans integral with said air operated frame operating power cylindermeans to cause the pivotal movement after the jaw means has beenextended and the part gripped, a pair of high pressure air hose meansconnected to said air operated jaw operating power cylinder means andsaid air operated frame operating power cylinder means to deliver highpressure air thereto and to exhaust air therefrom, said air operated jawoperating power cylinder means and said air operated frame operatingpower cylinder means being connected in series, first and second pivotalconnecting means between said air operated frame operating powercylinder means and said frame means, one of said air hose means beingconnected to said power cylinder means through one of said pivotalconnecting means, and the other of said air hose means being connectedto said power cylinder means through the other of said pivotalconnecting means.
 2. A control system for a press unloader having amovable arm carrying jaw means movable between a retracted position andan extended position for gripping a part in a die cavity and forcarrying the part away from the die cavity, comprising air operated jawoperating power cylinder means for moving the jaw means between theextended position and the retracted position, frame means pivotallysupporting said jaw operating power cylinder means and said jaw means,air operated frame operating power cylinder means for pivotally movingsaid frame means jaw operating power cylinder means and said jaw meansbetween a part gripping position and a part lifting position whereby agripped part is lifted from a die cavity in a press with which the pressunloader is associated, timing means integral with said air operatedframe operating power cylinder means to cause the pivotal movement afterthe jaw means has been extended and the part gripped, an air cylinderhaving spaced end walls, piston means in said air cylinder movabletherein by air pressure during and after movement of said jaw means tothe extended position, piston rod means operable by said piston andoperably associated with said frame means to cause pivotal movementthereof, and connecting means operable after the movement of said jawmeans to the extended position to connect said piston means and saidpiston rod means to said frame means to cause pivotal movement thereof,said piston means being slidably supported on and movable relative tosaid piston rod means during the first portion of the piston movement,said piston means being movable relative to said piston rod means duringmovement of said jaw means to the extended position, and said connectingmeans connecting said piston means to said piston rod means aFter themovement of said jaw means to the extended position during the lastportion of the movement of said piston means.
 3. The invention asdefined in claim 2 and there being air flow rate adjustment means tocontrol the rate of movement of said piston means by controlling therate of flow of air to enable said jaw means to reach the extendedposition before said connecting means is effective to connect saidpiston means to said piston rod means.
 4. The invention as defined inclaim 3 and wherein said connecting means comprising spaced abutmentflanges on said piston rod means engageable with said piston means aftersliding movement of said piston means therebetween.
 5. The invention asdefined in claim 4 and wherein said spaced abutment flanges alternatelyengaging opposite ones of said spaced end walls of said air cylinder andbeing held thereagainst by high pressure air until said piston meansengages one of said abutment flanges and moves said rod means.
 6. Acontrol system for a press unloader having a movable arm carrying jawmeans movable between a retracted position and an extended position forgripping a part in a die cavity and for carrying the part away from thedie cavity, comprising air operated jaw operating power cylinder meansfor moving the jaw means between the extended position and the retractedposition, frame means pivotally supporting said jaw operating powercylinder means and said jaw means, air operated frame operating powercylinder means for pivotally moving said frame means jaw operating powercylinder means and said jaw means between a part gripping position and apart lifting position whereby a gripped part is lifted from a die cavityin a press with which the press unloader is associated, timing meansintegral with said air operated frame operating power cylinder means tocause the pivotal movement after the jaw means has been extended and thepart gripped, a first frame means fixed to the movable arm, a secondframe means pivoted to the first frame means and supporting said jawmeans, said frame operating power cylinder means comprising an aircylinder, a movable piston, and a piston rod, a first pivotal connectingmeans pivotally mounting said frame operating power cylinder meansbetween said air cylinder and said first frame means on said first framemeans, a second pivotal connecting means between said piston rod andsaid second frame means whereby said frame operating power cylindermeans is movable relative to said first frame means and said secondframe means during pivotal displacement of said second frame means, airhose means connected to said frame operating power cylinder means tosupply high pressure air thereto and exhaust air therefrom, a first airhose connection integral with said first pivotal connecting means, firstair passage means extending from said first air hose connection throughsaid first pivotal connecting means to one side of said piston, a secondair hose connection integral with said second pivotal connecting means,and second air passage means extending from said second air hose throughsaid second pivotal connecting means and said piston rod to the otherside of said piston.
 7. The invention as defined in claim 6 and furthercomprising adjustable valve means in each of said first and secondpassage means to variably control the rate of flow of high pressure airto said air cylinder.